Simple example that shows Skunk leaking database query/command arguments to tracing and logging. These arguments can contain sensitive data, PII, etc, which should not be exposed to tracing/logging backends.

This example is based on the Skunk command example and uses the Natchez log tracing backend.

docker compose up -d
sbt run

Note that Skunk leaks all inserted data to the tracing backend, in the arguments field of the bind trace:

  "arguments" : "Bob,12",
  "arguments" : "John,2,George,3,Paul,6,Ringo,3",

On a Postgres error/exception (e.g. primary key violation), Skunk leaks the arguments to the tracing backend in the error.argument.n.value fields:

  "error.argument.1.value" : "Bob",
  "error.argument.2.value" : "12",

And the error.detail field:

 "error.detail" : "Key (name)=(Bob) already exists."

If the Postgres error/exception occurs within a transaction, then something within Skunk appears to log the error, with arguments, directly to stdout/stderr. We have not found a way to prevent this.

skunk.exception.PostgresErrorException:
🔥
🔥  Postgres ERROR 23505 raised in _bt_check_unique (nbtinsert.c:664)
🔥
🔥    Problem: Duplicate key value violates unique constraint "pets_pkey".
🔥     Detail: Key (name)=(Bob) already exists.
🔥
🔥  The statement under consideration was defined
🔥    at /Users/ZCox/code/zcox/skunk-arguments-tracing-example/src/main/scala/Main.scala:27
🔥
🔥    INSERT INTO pets VALUES ($1, $2)
🔥
🔥  and the arguments were provided
🔥    at /Users/ZCox/code/zcox/skunk-arguments-tracing-example/src/main/scala/Main.scala:48
🔥
🔥    $1 varchar    Bob
🔥    $2 int2       12
🔥
🔥  If this is an error you wish to trap and handle in your application, you can do
🔥  so with a SqlState extractor. For example:
🔥
🔥    doSomething.recoverWith { case SqlState.UniqueViolation(ex) =>  ...}
🔥

skunk.exception.PostgresErrorException: Duplicate key value violates unique constraint "pets_pkey".
  at skunk.net.protocol.Execute$$anon$1$$anonfun$$nestedInanonfun$apply$2$1.$anonfun$applyOrElse$8(Execute.scala:69)
  at flatten$extension @ skunk.util.Pool$.$anonfun$ofF$2(Pool.scala:103)
  at flatMap @ skunk.net.BufferedMessageSocket$$anon$1.$anonfun$receive$1(BufferedMessageSocket.scala:150)
  at get @ skunk.util.Pool$.free$1(Pool.scala:156)
  at flatMap @ skunk.net.BufferedMessageSocket$$anon$1.receive(BufferedMessageSocket.scala:147)